[LU-17091] check correct return value in lfs_df

• Type: Bug
• Resolution: Fixed
• Priority: Minor
• Fix Version/s: Lustre 2.16.0
• Severity: 3
• Assignee: Feng Lei
• Reporter: Feng Lei

Description

test-framework.sh, function lfs_df, $? is the return value of last command. To check the return value of the first command, it should be ${PIPESTATUS[0]}.